The present invention relates to a semiconductor device technique, and, more particularly, to a technique that is effective for application to an RF (Radio Frequency) power module.
An RF power module is an electronic part for signal amplification, which is used in a communication device, such as, for example, a cellular phone or the like. The RF power module includes an amplifier circuit for signal amplification and a power supply or source control circuit, which supplies a desired power supply voltage to the amplifier circuit. A switching element of the power supply control circuit selects between a supply and non-supply of the desired power supply voltage to the amplifier circuit. The switching element comprises, for example, a bipolar transistor or MOS·FET (Metal Oxide Semiconductor Field Effect Transistor). The semiconductor chip in which the switching element is formed is packaged separately from the semiconductor chip that constitutes the amplifier circuit. The semiconductor chip is mounted on a printed circuit board equipped with the power module.
Incidentally, a high-frequency power amplifier device having a plurality of amplification systems, and a multiband communication type wireless communication device having the high-frequency power amplifier device, have been disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-111415 (see Patent Document 1).
Patent Document 1
                Japanese Patent Application Laid-Open No. 2002-111415        